Information Systems graduate student Nobuhiro Takahashi at Tokyo’s University of Electro-Communications has been working on SHIRI, a “humanoid buttocks robot” that is primed to express “various emotions with organic movement of the artificial muscles.” In the video, this butt robot is shown reacting to being spanked, slapped, caressed and stroked. The giver feels SHIRI brace (at the 2:32 mark) and express a “happiness” response (at the 2:47 mark).